Hi trident, i´m not skilled at all, the only thing i could do were making the circuit and pray for nothing get burned when it were plugged, thats because i ask about it. This is too dificult for me, i simulated the circuit on LTspice application, and everything seemed easy. Your last post is chines...

Ok, thanks trident.

So, i only have to add a voltage divider between PWM output of my video card and the MAXIM circuit; it sounds easier than redesing all the circuit with oder components, as i have planed.

Thanks a lot, you helped me very much.

Hi trident, thanks for your answer, and sorry for the not enough information, i thought the less i wrote, the less mistakes i made, my english is not as good as i wish. Your guess is right, i would like to use it to convert PWM output, of my gpu fan controler (i mean the one the video card has), in ...

Hi all,
i have a question about the Maxim AN3149 circuit, is it ok for using it with a low frequency (two pin) pwm controler?

Thanks.

Can I ask why you can't just run your fan from the pwm header, though? The only reason is because my motherboard has 4-pin headers, and if i`m not wrong the pwm pin is at 5V and its max current is 5mA [(5-0.7)/1.8K= ~2mA], but that i don`t kow is if i must keep in mind anything else or only the cur...

hi, i have done a circuit like this with a NPN transistor to use it as a switch controlled by the fourth pin (pwm) of my amd motherboar header. Knowing that base current isn`t more than 5 mA (the max pwm current according to the specification of this threat ) and the current gain of the transistor i...

i will start in the 2.5" category: Samsung MP0804H 80GB @5400rpm: seek is almost inaudible , possibly drowned by the spindle noise! It has a pink noise sort of sound, almost like a 40mm fan on steroids... fairly interesting, thats now the second modern 2.5" drive I have read called too noisy. allth...

3-pin fan & 3-pin pwm header = fan works in pwm mode, it will make more or less noise depending on which fan you use. 3-pin fan & 4-pin pwm header = motherboard supports pwm but the fan doesn`t work in this mode, it works at full speed instead. 4-pin fan & 3-pin header = motherboard doesn`t support ...

pcy wrote:Hi,


You mean you want to see a pic, or you want me to send you one?



Peter

Sorry about my bad english, i mean i`m waiting for its presentation,

Hi, my 120mm globe fan starts perfectly, without any kickstart circuit, at 5V and it spins at 500 rpm at this voltage, but it is quiet at 700 rpm. This fans works at very low voltage, some 80mm globe fans i have start at 3v, i haven`t tested the 120mm fan, but it should work at 3v with kickstart or ...

Ok, i`m anxious to see it.

Weel, ok. Hi, I have a similar product. So far we have only built protptypes, but they work fine controlling varuous 3 pin fans using the PWM output fro an Intel DP965LT mobo. I was thinbking of making them available for about £5 - $9.50 plus postage... Peter Have you tested this prototipes yet? is...

Hi all, i`m not an electronic expert, so according to 4-wire pwm pin features, could i use a npn transistor like this to manage the speed of a fan with this circuit? http://img515.imageshack.us/img515/9169/circuit3kh8.th.gif It works in 3-pin pwm headers, but i`m afraid of very low current allowed i...